1. for access to reviews and discussion of the 2016 and 2017 Ford Explorer, Tech Tips, How to Articles, Off-Road Modification, Events, and more!

    Register Today It's free! This box will disappear once registered!

Rough Idle then throws P1151 code

Discussion in 'Under the Hood' started by hunterdan, October 3, 2006.

  • Searches ExplorerForum.com
    1. hunterdan

      hunterdan Well-Known Member

      Joined:
      October 21, 2004
      Messages:
      1,383
      Likes Received:
      0
      Trophy Points:
      0
      City, State:
      Fairless Hills, Pa
      Year and Model:
      2010 Chevy Silverado
      My 98 OHV sport has recently been acting up. I frequently make 100+ mile runs between Harrisburg and Philadelphia. The trip is almost 100% highway. Whenever I come to a complete stop or where the truck would just idle along after a long period of highway driving, it will idle rough, about 500 RPM or lower. Usually if I hit the gas it will take care of the idle and then idle normally. On my last 2 trips out to Harrisburg, I stopped at a rest stop about midway, the first time was to fill up, the latest was a coffee stop. Both times the idle would be rough when comming to a stop when idling, and then after about 5 minutes of highway driving again, the CEL came on. The code was read to be P1151 which I know is one of the O2 sensors. Both upstream sensors are just over a year old. I am also noticing a delayed acceleration when depressing on the throttle. It doesn't seem to be tranny related, but more like the engine is lugging, then all of a sudden its got more power and I start to pull away much harder. If I were to guess, I would say my problem is with the EGR system, but the P1151 code is throwing me off. I pulled the driver's side O2 sensor and sprayed cleaner in it trying to help. The really odd thing is, it only does it on my way to Harrisburg, never on my way back home to Philly. Also, my mileage out there was much worse even though i was cruising at 65, but on the way back I got over 20 mpg at 75+ mph. Any suggestions on what the problem may actually be? I have a homemade PVC intake, but have tried the stock intake tube and still had the rough idle. The CEL is a new development, although it goes out on its own after a day or so. The lack of power seems to be more prevalent after the rough idle has occurred, it was very bad on a trip to Bloomsburg a few weeks ago, but never tripped the CEL. Please help, any suggestions would be very helpful.

      Dan
       
    2. Support EF


      Join the Elite Explorers for $20 a year

      Explorer Forum has probably saved you that much already, and will continue to save you money as you learn how to diagnose and fix problems yourself, and learn which modifications work without having to experiment on your own. Elite Explorer members see practically no ads, add your own profile photo, upload photo attachments directly to your posts and Media Gallery, create more private Conversations, and more. Join Today. Your support is greatly appreciated.



      to hide adverts.
    3. hunterdan

      hunterdan Well-Known Member

      Joined:
      October 21, 2004
      Messages:
      1,383
      Likes Received:
      0
      Trophy Points:
      0
      City, State:
      Fairless Hills, Pa
      Year and Model:
      2010 Chevy Silverado
      Anybody? Any ideas where to start?
       
    4. cgriffin_5139

      cgriffin_5139 B

      Joined:
      October 11, 2005
      Messages:
      3,525
      Likes Received:
      0
      Trophy Points:
      0
      Fix for a Missing Engine

      Posted by: Jack Lobdell

      Many Explorer owners have experienced "bogging" or "missing" or just unsteady performance in their 4.0 engine and have been frustrated by lots of expensive "non-fixes". After riding on a plane next to a manufacturing trainer from a company that builds OEM replacement auto electrical components for places like AutoZone and CarQuest, I tried his tip. He says that Ford have these problems more than other makes and the 4.0 engine seems to be more susceptible to the problem than other Ford engines.

      It seems that a "missing" engine culprit is actually the computer's sensor inside the Mass Air Flow Sensor (MAF). It eventually just gets a little dirty or builds up its own patina in the filament wires. A dirty or slightly patinated filament will send the wrong air reading to the computer, saying it is getting more air than it really is and the computer will tell the EFI to send in the wrong mix of fuel, thus, the bogging. The patina seems to form faster if you live in a damp climate. I don't so here in New Mexico mine went 82K before it developed a small "flat idle spot"…it would run just fine but the idle began to drop every few revs from 700 to 500. No big deal.

      If you have had bogging or missing or idle spots, about every 25K miles plan on this quick cleaning job:
      When your engine is cool, remove the wiring clip from the side of the black plastic sensor part of the MAF aluminum body. To remove the MAF interior sensor wire, you will need a Security Star (Size T15 or T20) screwdriver or screwdriver bit for a power screwdriver. Remove the two security star-head screws and carefully remove the sensor. You will see the two sensor filaments…they look almost like the filaments on a light bulb. Carefully spray the filaments with an O2 safe carburetor cleaner, such as Gumout. Let it dry thoroughly. I help mine along with a careful blast or two of canned dry air. While it is drying carefully wipe the aluminum mount surface of the MAF body if there is any dust there, but be careful not to get dust in the mount hole. When the sensor is dry, replace the sensor back in the MAF body and secure with the security star-head screws. These don't need to be torqued down, just simply hand tight. Replace the wiring clip. Then start up your engine. You should have solved any bogging or missing problems. My flat idle spot is ancient history.

      try this it might help
       
    5. hunterdan

      hunterdan Well-Known Member

      Joined:
      October 21, 2004
      Messages:
      1,383
      Likes Received:
      0
      Trophy Points:
      0
      City, State:
      Fairless Hills, Pa
      Year and Model:
      2010 Chevy Silverado
      Cleaned the MAF a few times, I do have a spare one in the garage that I may try tomorrow.

      Dan
       
    6. ma96782

      ma96782 Well-Known Member

      Joined:
      January 21, 2006
      Messages:
      1,123
      Likes Received:
      0
      Trophy Points:
      0
      City, State:
      Vancouver, WA
      Year and Model:
      '94 XLT, 4dr
    7. hunterdan

      hunterdan Well-Known Member

      Joined:
      October 21, 2004
      Messages:
      1,383
      Likes Received:
      0
      Trophy Points:
      0
      City, State:
      Fairless Hills, Pa
      Year and Model:
      2010 Chevy Silverado
      Thanks for that link, it seems to describe several of my symptoms. I have not yet swapped out maf elements, but that will be first on my list tomorrow. Thanks again.

      Dan
       
    8. hunterdan

      hunterdan Well-Known Member

      Joined:
      October 21, 2004
      Messages:
      1,383
      Likes Received:
      0
      Trophy Points:
      0
      City, State:
      Fairless Hills, Pa
      Year and Model:
      2010 Chevy Silverado
      Turns out the spare MAF element I have is a different plug design and won't work. I'm still exhibiting the symptoms I described above. I've cleaned the MAF several times, but to no avail. The rough idle, and lugging with sudden power surge is still happening after getting off the highway. Tomorrow I will be searching for a leaking intake manifold gasket. I really want to get a scanner hooked up and look at the short and long term fuel trim to see where I stand, but I don't have access to one. I was also told it may be my idle air controller, but am doubtful. The EGR seems like a likely cause, but still am not sure. Anybody have any other ideas?

      Dan
       
    9. hunterdan

      hunterdan Well-Known Member

      Joined:
      October 21, 2004
      Messages:
      1,383
      Likes Received:
      0
      Trophy Points:
      0
      City, State:
      Fairless Hills, Pa
      Year and Model:
      2010 Chevy Silverado
      Still having same problem, but with a new Code

      Still Having the problem, but had it scanned the other day at Autozone and it pulled a P1151 and P1152. The P1152 is a new code as I was pulling the
      P1151 before. I'm now leaning towards the O2 sensor, but read somewhere that the EGR valve may be the cause. I'm limited on funds and I don't want to be throwing new parts at it that may or may not fix the problem. I've cleaned the MAF a number of times already, cleaned the IAC and still have not had any luck. I did not clear the codes, but after about 2 days the light went off on its own. Anybody have ANY ideas at all?:confused:
       
    10. hunterdan

      hunterdan Well-Known Member

      Joined:
      October 21, 2004
      Messages:
      1,383
      Likes Received:
      0
      Trophy Points:
      0
      City, State:
      Fairless Hills, Pa
      Year and Model:
      2010 Chevy Silverado
      Figured I would post an update to this. The issue has been cleared. I replaced both O2 sensors up front and this cleared out all codes and all driveability problems. I replaced the bosch sensors with SNG units, which were considerably cheaper, but still seem well made. Also, the heads of the old 02 sensors were a rusty red color. A little burnt out maybe? I do think I know what caused the early demise of the bosch units though. Thought I would post this to let everyone else know. I almost forgot, the code I had just before I changed the sensors changed from P1151 to P0... about lean on bank 2 sensor one or something. Hope this helps others.

      Dan
       
    11. rd_turbo

      rd_turbo Active Member

      Joined:
      February 17, 2005
      Messages:
      120
      Likes Received:
      0
      Trophy Points:
      0
      City, State:
      Mississauga, ON
      Year and Model:
      '98 B3000 4X4
      Dan,

      I read with great interest your thread and others' posts and links. I'm trying to get my head around a similar issue on my 98 B3000. Although the vehicles are quite different, I'm hoping that what I just read may apply...even if only in general terms. My problems started on the return portion of a trip to Ohio (a pretty substantial elevation difference from where I live) and I think my system may have made some improper corrections based on improper MAF readings.
       
    12. rondhol

      rondhol New Member

      Joined:
      February 2, 2009
      Messages:
      2
      Likes Received:
      0
      Trophy Points:
      0
      City, State:
      tally, fl
      Only on closed loop/warm engine

      I feel flat idle drop from 700 to 500 every 30 seconds after the engine is warm. It runs fine when drive and can go to redline rpm. MAF was cleaned several times with no luck and p0171 comes and goes without by itself. Could it be the O2 sensor? But there is no code from O2 sensor. Actually my car is Nissan Altima 02 but this forum give me a strong reason to discuss with.
       
    13. areed

      areed New Member

      Joined:
      May 11, 2010
      Messages:
      3
      Likes Received:
      0
      Trophy Points:
      0
      City, State:
      clifton, new jersey
      Year and Model:
      '97 XLT
      97 explorer 4.0 OHV

      i also have the same problem, the truck seems to bog down to 400 rpms when im stopped then idle normally, it also boggs and stumbles upon acceleration and then suddenly gets a boost of power. i also have a horrible misfire odor coming from the exhaust. so far ive replaced the air filter, the spark plugs, ignition wires, and the upper intake manifold gasget. i just brought a scanner today and i got the p0151 code which was bad 02 sensor in bank 2 and the p1151 which also points to an 02 sensor however im skeptical that faulty 02 sensors would cause such a major problem in engine performance so im inclined to believe theres something else causing the problem
       
    14. hunterdan

      hunterdan Well-Known Member

      Joined:
      October 21, 2004
      Messages:
      1,383
      Likes Received:
      0
      Trophy Points:
      0
      City, State:
      Fairless Hills, Pa
      Year and Model:
      2010 Chevy Silverado
      You'd be surprised how a bad O2 sensor would make a car run. If you are getting the P0151, I'd recommend replacing the sensor.
      http://www.obd-codes.com/p0151
      In my case, the fact that the sensors weren't switching and the low voltage codes, the truck couldn't regulate the fuel at idle when there is very little air being ingested. The O2 sensors are one of the major keys to making fuel injection work. If they don't work there is no way to accurately tell how much fuel is being burned. You could run rich, or lean, or bounce back and forth between the two.

      Dan
       
    15. ague00

      ague00 New Member

      Joined:
      May 23, 2010
      Messages:
      2
      Likes Received:
      0
      Trophy Points:
      0
      City, State:
      miami
      Year and Model:
      2001
      Hi All,

      I've had the same issues for some time now, but was always hesitant to bring my 2001 explorer sport to the dealer. Strangely the same codes come up every year in the winter season only when the engine is colder (P1151, P0174, P0301 to 05). To warm the engine I have to keep the throttle up, Ones at a certain temperature it runs ok. I will try both solutions and let you know , thanks
       
    16. swetrid

      swetrid Well-Known Member

      Joined:
      September 30, 2010
      Messages:
      1,896
      Likes Received:
      1
      Trophy Points:
      0
      City, State:
      Reading Pa
      Year and Model:
      1999 Eddie Bauer
      Sounds like you have bad intake gaskets.
       
    17. ague00

      ague00 New Member

      Joined:
      May 23, 2010
      Messages:
      2
      Likes Received:
      0
      Trophy Points:
      0
      City, State:
      miami
      Year and Model:
      2001
      Will check it out as well , thanks
       

    Share This Page








    We Support Our Troops!